1. Field of the Invention
The present invention relates to a modified fuel burning gas turbine, which is operated using, as fuel, modified oil prepared by heating and pressurizing heavy oil and mixing the heavy oil with high-temperature, high-pressure water for property modification and lightening of the oil. The present invention also relates to a method of operating the gas turbine.
2. Description of the Related Art
A combined gas turbine is well known which is operated using, as fuel, modified oil prepared by heating and pressurizing heavy oil and mixing the heavy oil with supercritical water for property modification and lightening of the oil. Such a technique is disclosed, for example, in Patent Reference 1 (JP,A 2000-109850).
With the disclosed technique, the heavy oil is pressurized to about 20 MPa by a pressurizing pump, and is heated to about 350° C. by heat exchange that is performed with exhaust gases at about 550° C. in a heat transfer pipe installed in an exhaust heat recovering boiler.
Similarly, supply water is pressurized to about 20 MPa by a pressurizing pump, and is heated to about 450° C. by heat exchange that is performed with the exhaust gases at about 550° C. in a heat transfer pipe installed in the exhaust heat recovering boiler.
The heated and pressurized heavy oil and the water in a supercritical state are mixed with each other in a modifying unit to produce fuel-purpose modified oil. The fuel-purpose modified oil is depressurized through a depressurizing valve and supplied to a combustor, thereby driving a gas turbine. Further, steam produced in the exhaust heat recovering boiler drives a steam turbine.